Absorbent Pant With Advantageously Channeled Absorbent Core Structure And Bulge-Reducing Features

ABSTRACT

A disposable absorbent pant having a belt structure that encircles the wearer&#39;s waist, with front and rear belt portions, and a longitudinally channeled absorbent core structure, is disclosed. The channels are extended so as to underlie at least one of the front and rear belt portions, thereby providing added structural support to restrain the absorbent core and reduce the likelihood of undesirable bulging in the front and/or rear of the pant while it is worn, after the core has absorbed liquid and stiffened longitudinally as a result of the channeled structure.

BACKGROUND OF THE INVENTION

In order to maintain or grow their market share, manufacturers ofdisposable absorbent articles such as disposable diapers and absorbentpants must continue to discover and develop improvements to materials,components and features that affect aspects such as containment,absorbency, comfort, fit and appearance. Absorbent pants aremanufactured in smaller sizes to be used as, e.g., pull-on diapers andtoilet training pants for young children, and in larger sizes to be usedas, e.g., undergarments for persons such as adults or older childrensuffering from incontinence. In some applications the consumer and/orwearer may prefer that the article have an appearance and feelresembling ordinary underwear when worn.

A particular type of absorbent pant design currently marketed issometimes called the “balloon” pant. The balloon pant design usuallyincludes a central absorbent chassis including the absorbent core and anelastic belt. The elastic belt is usually relatively wide (in thelongitudinal direction) and elastically stretchable in the lateraldirection. It entirely encircles the wearer's waist, and thereby coversa relatively large amount of the wearer's skin, and also makes up arelatively large portion of the visible outside surfaces of the pant.The belt is often formed of two layers of nonwoven web sandwiching oneor more elastic members such as a plurality of laterally-orientedstrands or strips of elastomeric material, or a section of elastomericfilm, elastomeric scrim or elastomeric nonwoven. It is common among suchdesigns that, in manufacture, the elastic member(s) are sandwichedbetween the nonwoven web layers while in a strained condition.

The absorbent core structure that is part of the central chassis portionplays an important role in containment and absorbency of exudates, aswell as in comfort, fit and appearance of the article when worn. Inrecent years, absorbent core designs have progressed toward structureswith relatively higher proportions by weight of absorbent polymerparticles and lower proportions of absorbent fiber (e.g., cellulosefiber), resulting in structures that are thinner than absorbent coredesigns of earlier years and enabling manufacture of products that areless bulky and more closely-fitting (e.g., more underwear-like) whendry. The latter structures, however, can be slower in liquid acquisitionrate, and because of their greater proportions of absorbent polymerparticles, can become saggy, bulky and gelatinous when wetted. Toaddress these issues, absorbent structures includinglongitudinally-oriented channels have been developed. Appropriatelylocated and structured longitudinal channels can help distribute liquidalong deposits of absorbent polymer particles along the length of theabsorbent core, and thereby help improve acquisition rate. They also canhelp reduce chances of a saggy and bulky appearance of the article whenwetted, by providing longitudinal structural rigidity through the crotchregion of the article resulting from pressure within the wettedabsorbent polymer particle deposits between the channels.

However, it has been discovered that this structural rigidity may haveundesirable effects on appearance, fit and and/or comfort. Inparticular, the longitudinal structural rigidity can cause the frontand/or rear regions of the absorbent core to tend to bulge outwardlyfrom the wearer's body in the front and/or rear, resulting in bulkyprotrusion(s) that can create an unsightly appearance and adverselyimpact comfort.

Thus, there continues to be room for improvements in absorbent pantdesign that enable realization of the benefits of various developmentsto date while mitigating adverse effects of these features, both whenthe pant is dry, and after it is wetted.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings, the same features are numbered consistently throughoutthe various views and depictions of examples.

FIG. 1 is a front perspective view of an example of a balloon pant.

FIG. 2A is a schematic plan view of a balloon pant precursor structure,prior to joining of the front and rear belt portions at side seams,wearer-facing surfaces facing the viewer.

FIG. 2B is a schematic plan view of a balloon pant precursor structure,prior to joining of the front and rear belt portions at side seams,wearer-facing surfaces facing the viewer.

FIG. 2C is a schematic plan view of a balloon pant precursor structure,prior to joining of the front and rear belt portions at side seams,wearer-facing surfaces facing the viewer.

FIG. 3 is a schematic, exploded perspective view of components of a beltportion.

FIG. 4 is a schematic, close-up plan view of an area of a belt portion.

FIG. 5 is a schematic cross section of the area of the belt portionshown in FIG. 4.

FIG. 6A is a schematic side view of a pant.

FIG. 6B is a schematic side view of a pant.

FIG. 7 is a schematic side view of a pant, shown in one configuration asloaded with absorbed liquid.

FIG. 8 is a schematic perspective view of an absorbent structureincluding an absorbent layer with two longitudinal main channels inaccordance with one non-limiting example.

FIG. 9 is a schematic perspective view of an absorbent layer with fourlongitudinal main channels in accordance with one non-limiting example.

FIG. 10A is a schematic top/plan view of an absorbent structureincluding an absorbent layer with four longitudinal main channels inaccordance with one non-limiting example.

FIG. 10B is a schematic perspective view of the absorbent structure ofFIG. 10A, shown in a flexed position.

FIGS. 11A to 11E are schematic plan view representations of channelconfigurations in accordance with various non-limiting examples.

FIG. 12 is a schematic perspective view of an absorbent layer includingtwo longitudinal main channels in the crotch region and two secondarychannels in the front region in accordance with one non-limitingexample.

FIG. 13 is a schematic perspective view of an absorbent layer includingtwo longitudinal main channels in the crotch region, two secondarychannels in the front region and two secondary channels in the backregion in accordance with one non-limiting example.

FIG. 14 is a schematic top/plan view of an absorbent structure withabsorbent layer including two longitudinal main channels in the crotchregion, and two secondary channels at front and rear, in accordance withone non-limiting example.

FIG. 15A is a schematic lateral cross-section view of an absorbentstructure with longitudinal channels in accordance with one non-limitingexample.

FIG. 15B is a schematic lateral cross-section view of an absorbentstructure in accordance with one non-limiting example.

FIG. 16A is a schematic plan view of a non-limiting example of a balloonpant precursor structure, prior to joining of the front and rear beltportions at side seams, wearer-facing surfaces facing the viewer, shownwith a configuration of longitudinal main channels.

FIG. 16B is a schematic plan view of an alternate balloon pant precursorstructure, prior to joining of the front and rear belt portions at sideseams, wearer-facing surfaces facing the viewer, shown with aconfiguration of longitudinal main channels.

FIG. 16C is a schematic plan view of an alternate balloon pant precursorstructure, prior to joining of the front and rear belt portions at sideseams, wearer-facing surfaces facing the viewer, shown with anotherconfiguration of longitudinal main channels.

FIG. 16D is a schematic, exploded longitudinal cross section view of aportion of the structure depicted in FIG. 16A.

FIG. 17 is a schematic plan view of an alternate balloon pant precursorstructure, prior to joining of the front and rear belt portions at sideseams, wearer-facing surfaces facing the viewer, shown with anotherconfiguration of longitudinal main channels and secondary channels.

FIG. 18 is a schematic plan view of an alternate balloon pant precursorstructure, prior to joining of the front and rear belt portions at sideseams, wearer-facing surfaces facing the viewer, shown with anotherconfiguration of longitudinal main channels and secondary channels.

FIG. 19 is a schematic plan view of an alternate balloon pant precursorstructure, prior to joining of the front and rear belt portions at sideseams, wearer-facing surfaces facing the viewer, shown with anotherconfiguration of longitudinal main channels and secondary channels.

FIG. 20 is a schematic plan view of a balloon pant precursor structure,prior to joining of the front and rear belt portions at side seams,garment-facing surfaces facing the viewer, shown with a configuration oflongitudinal main channels and non-elasticized zones in front and rearbelt portions.

DETAILED DESCRIPTION OF THE INVENTION

As used herein “absorbent core” refers to a component of an absorbentarticle disposed between a topsheet and backsheet of an absorbentarticle. The absorbent core of an absorbent article may include one ormore absorbent structures and optionally further layers, such as, forexample, a cover layer.

“Absorbent polymer particles” as used herein refers to substantiallywater-insoluble polymer particles that can absorb at least 10 timestheir weight of a 0.9% saline solution in de-mineralized water asmeasured using the Centrifuge Retention Capacity test (EDANA 441.2-01).

As used herein “absorbent structure” refers to a three dimensionalstructure useful to absorb and contain liquids, such as urine. Theabsorbent structure may be the absorbent core of an absorbent article ormay be part of the absorbent core of an absorbent article, i.e. anabsorbent component of the absorbent core, as will be further describedherein.

The term “basis weight” as used herein refers to the mass of a materialper unit surface area it occupies when laid out on a flat surface, e.g.the mass of absorbent polymer particles deposited per unit surface areaof a supporting substrate, expressed in, e.g., grams per square meter(gsm).

Referring to FIGS. 2A-2C, the “crotch region” of a pant is the portionthrough which the lateral axis (herein, axis x) passes, and whichextends longitudinally one-sixth of the overall length of the pantfrontward and rearward of the lateral axis. Accordingly, the frontregion includes the front one-third of the overall length of the pant;the crotch region includes the middle one-third of the length of thepant; and the rear region includes the rear one-third of the overalllength of the pant.

As used herein “diapers” refers to devices which are intended to beplaced against the skin of a wearer to absorb and contain the variousexudates discharged from the body. Diapers are generally worn by infantsand incontinent persons about the lower torso so as to encircle thewaist and legs of the wearer. Examples of diapers include infant oradult diapers and disposable absorbent pants such as training pants andadult-incontinence pants.

“Disposable” is used herein to describe articles that are generally notadapted to be laundered or otherwise cleaned, restored or reused (i.e.,they are only adapted to be durable enough to be used once, and thendiscarded, and may be recycled, composted or otherwise disposed of).

Throughout the present description, a material or composite of materialsis considered to be “elastic” or “elastomeric” if, when a biasing forceis applied to the material, the material or composite may be extended toan elongated length of at least 150% of its original relaxed length(i.e. can extend at least 50%), without rupture or breakage whichsubstantially damages the material or composite, and when the force isremoved from the material or composite, the material or compositerecovers at least 40% of such elongation. In various examples, when theforce is removed from an elastically extensible material, the materialor composite may recover at least 60% or even at least 80% of itselongation.

“Elongation,” used herein to quantify and express an amount of strainimparted to an elastic strand in the direction of its longitudinal axis,means: [(strained length of the strand−length of the strand beforestraining)/(length of the strand before straining)], x 100%. Where theterm “pre-strain” is used to refer to elongation imparted to an elasticstrand during manufacture of a belt structure or pant, it refers toelongation, expressed in the same manner.

“Film” means a macroscopically continuous skin-like or membrane-likelayer of material formed of one or more polymers. “Film” isdistinguished from “nonwoven web” or “nonwoven” in that the latter has aform consisting of a web-like structure of consolidated butpredominately individually distinct fibers.

“Hot melt adhesive” as used herein refers to adhesives conforming withthe description given in “Adhesion and Adhesives Technology: AnIntroduction” by Alphonsus V. Pocius (Hanser publishers Munich, 1997).Therein a hot melt is defined as an adhesive applied from the melt andgaining strength upon solidification.

“Lateral”—with respect to a pant and its wearer, refers to the directiongenerally perpendicular to the wearer's standing height, i.e., thehorizontal direction when the wearer is standing. “Lateral” and“transverse” (and forms thereof) also refer to the directionperpendicular to the longitudinal direction. With respect to certain ofthe figures herein in which it is shown, the x-axis lies along thelateral and/or transverse direction.

“Longitudinal”—with respect to a pant and its wearer, refers to thedirection generally parallel to the wearer's standing height, i.e., thevertical direction when the wearer is standing. “Longitudinal” is alsothe direction generally parallel to a line extending from the midpointof the front waist edge, between the leg openings, to the midpoint ofthe rear waist edge of the pant, when the pant structure is separated atthe side/hip seams and laid out unfolded, extended and flat. Withrespect to certain of the figures herein in which it is shown, they-axis lies along the longitudinal direction.

Used to describe a feature, “longitudinally-oriented” means that thelargest dimension of the feature has a longitudinal-direction vectorcomponent that is greater than its lateral-direction vector component.Conversely, “laterally-oriented” means that the largest dimension of thefeature has a lateral-direction vector component that is greater thanits longitudinal-direction vector component.

With respect to a pant, relative positional terms such as “lower,”“lowest”, “above,” “below,” “bottom,” etc., and forms thereof, areexpressed with respect to the vertically lowermost extent (in the crotchregion) and uppermost extent (at the waist edges) of the pant structurealong a vertical direction, when worn by a standing wearer. With respectto a precursor structure to the pant, the lowest portion is at thelateral axis (axis x depicted in the figures) and the highest portionsare at the waist edges.

A “nonwoven” is a manufactured sheet or web of directionally or randomlyoriented fibers which are first deposited and accumulated onto a movingsurface (such as a conveyor belt) and then consolidated and bondedtogether by friction, cohesion, adhesion or one or more patterns ofbonds and bond impressions created through localized compression and/orapplication of pressure, heat, ultrasonic or heating energy, or acombination thereof. The term does not include fabrics which are woven,knitted, or stitch-bonded with yarns or filaments. The fibers may be ofnatural and/or man-made origin and may be staple and/or continuousfilaments or be formed in situ. Commercially available fibers havediameters ranging from less than about 0.001 mm to more than about 0.2mm and they come in several different forms: short fibers (known asstaple, or chopped), continuous single fibers (filaments ormonofilaments), untwisted bundles of continuous filaments (tow), andtwisted bundles of continuous filaments (yarn). Nonwovens may be formedby many processes including but not limited to meltblowing, spunbonding,spunmelting, solvent spinning, electrospinning, carding, filmfibrillation, melt-film fibrillation, airlaying, dry-laying, wetlayingwith staple fibers, and combinations of these processes as known in theart. The basis weight of a nonwoven is usually expressed in grams persquare meter (gsm).

“Pant,” as used herein, refers to a disposable absorbent garment havinga waist opening, leg openings and an absorbent structure at least in thecrotch region, adapted for wear by an infant, child or adult wearer. Apant may be placed in position on the wearer by inserting the wearer'sfeet into and through the waist opening and into the leg openings andsliding the pant up the wearer's legs into position about the wearer'slower torso. A pant may be preformed by any suitable techniqueincluding, but not limited to, joining together portions of the articleusing refastenable and/or non-refastenable bonds (e.g., seam, weld,adhesive, cohesive bond, fastener, etc.). A pant may be preformedanywhere along the circumference of the article (e.g., side fastened,front waist fastened).

In the following description, a surface of a wearable absorbent article,or of a component thereof, which faces the wearer when worn, is calledthe “wearer-facing surface.” Conversely, the surface facing away fromthe wearer is called the “garment-facing surface.” Accordingly, awearable absorbent article, and every sheet or web component thereof hasa wearer-facing surface and a garment-facing surface.

“z-direction,” with respect to a web, means generally orthogonal orperpendicular to the plane approximated by the web along the machine andcross direction dimensions.

Although examples of the structure of the invention are described hereinas used to form the belt of a balloon-type absorbent pant, it will beappreciated that examples may be used to form other components ofabsorbent pants, diapers and other wearable articles (includingdisposable forms thereof), and other products as well.

FIG. 1 depicts an example of balloon-type absorbent pant 10. FIGS. 2A-2Cdepict examples of the precursor structures of pants in an openconfiguration laid out flat and stretched out laterally againstelastic-induced contraction, wearer-facing surfaces facing the viewer,prior to final assembly in which front belt portion 22 is joined to rearbelt portion 23 at seams 24. To form pant 10, the precursor structuremay be folded at or about lateral axis x (located at the longitudinalmidpoint of the precursor structure) with the topsheet 33 facing inward,and the longitudinal edges of the front 22 and rear 23 belt portions maybe joined at seams 24, forming a pant structure having leg openings 15,front waist edge 34 and rear waist edge 35.

The pant structure may include a belt 20 and a central chassis 30.Central chassis 30 may include any combination of components found inthe absorbent structures of disposable diapers and absorbent pants,including but not limited to a liquid impermeable backsheet 31 formed atleast in part of liquid impermeable web material, a liquid permeabletopsheet 33, an absorbent core structure (described below), andelasticized barrier cuffs 32. Examples and descriptions of componentsand configurations of a central chassis may be found in U.S. Pat. App.Pub. No. 2013/0211355, as well as in the other references cited herein,to the extent not inconsistent herewith, wherein the chassis describedincludes components and features that may be included in central chassis30. In the example shown in FIG. 1, the front portion of belt 20 stopsshort of the crotch region 12 of the pant, at lower edge 21. Centralchassis 30 may overlie front and rear belt portions 22, 23 to the inside(wearer-facing side) thereof. The outer perimeter 41 of the centralchassis 30 may be defined by the outer perimeter of the liquidimpermeable web material.

In the examples suggested in FIGS. 2A and 2B, front and rear beltportions 22, 23 may be the outermost structures forming the front andrear regions of the pant. In the example suggested in FIG. 2C (also asshown in FIG. 16B), the pant may include an outer wrap 19 wrapping theentirety of the front, crotch and rear regions, and forming an outermostpant-shaped/profiled structure. Additional layer(s) and elastic membersto form front and rear belt portions 22, 23 may be disposed to theinside of outer wrap 19, and be suitably affixed thereto by adhesivelamination, bonding or any other suitable mechanism. An outer wrap 19may be formed of one or more sections of nonwoven web, and as reflectedin FIG. 2C, may be cut to a profile providing suitably tailored legopening edge profiles as desired.

Referring to FIGS. 3-5, one or both of front and rear belt portions 22,23 may be formed of layers of nonwoven web 25 a, 25 b, whichrespectively form inner and outer layers. Suitable nonwoven webmaterials that may be useful in the present invention also include, butare not limited to spunbond, spunlaid, meltblown, spunmelt,solvent-spun, electrospun, carded, film fibrillated, melt-filmfibrillated, air-laid, dry-laid, wet-laid staple fibers, and othernonwoven web materials formed in part or in whole of polymer fibers, asknown in the art. The nonwoven web may be formed predominately ofpolymeric fibers. In some examples, suitable non-woven fiber materialsmay include, but are not limited to polymeric materials such aspolyolefins, polyesters, polyamide, or specifically, polypropylene (PP),polyethylene (PE), poly-lactic acid (PLA), polyethylene terephthalate(PET) and/or blends thereof. In some examples, the fibers may be formedof PP/PE blends such as described in U.S. Pat. No. 5,266,392. Nonwovenfibers may be formed of, or may include as additives or modifiers,components such as aliphatic polyesters, thermoplastic polysaccharides,or other biopolymers. Further useful nonwovens, fiber compositions,formations of fibers and nonwovens and related methods are described inU.S. Pat. Nos. 6,645,569; 6,863,933; and 7,112,621; and in U.S. patentapplication Ser. Nos. 10/338,603; 10/338,610; and Ser. No. 13/005,237.

The individual fibers of which nonwoven layers 25 a and 25 b are formedmay be monocomponent or multicomponent (including bicomponent). Themulticomponent fibers may be bicomponent, with differing polymericcomponents in, e.g., a core-and-sheath or side-by-side arrangement. Theindividual components may include polyolefins such as polypropylene orpolyethylene, or their copolymers, or polyesters, thermoplasticpolysaccharides or other biopolymers.

According to one example, the nonwoven may include a material thatprovides good recovery when external pressure is applied and removed.Further, according to one example, the nonwoven may include a blend ofdifferent fibers selected, for example from the types of polymericfibers described above. In some examples, at least a portion of thefibers may exhibit a spiral curl which has a helical shape. According toone example, the fibers may include bicomponent fibers, which areindividual fibers each including different materials, usually a firstand a second polymeric material. It is believed that the use ofside-by-side bi-component fibers is beneficial for imparting a spiralcurl to the fibers. Examples of potentially suitable curled or “crimped”bicomponent fibers and nonwovens formed from them are described in U.S.Pat. Nos. 5,382,400; 5,418,045; 5,707,468; 6,454,989; 6,632,386;5,622,772 and 7,291,239. For purposes herein, use of a nonwoven formedof crimped bicomponent or multicomponent fibers such as, for example,described in the patents and/or patent applications cited immediatelyabove, may be desired as one both layers 25 a, 25 b used to form thebelt portions, because they can feel particularly soft to the touch (forwearer comfort on the inside and aesthetically pleasing feel on theoutside) and are generally quite pliable, making them easily drawnlaterally at the lower rear leg edges as will be described below.

Referring to FIGS. 3-5, layers of nonwoven web 25 a, 25 b may sandwichone or more elastic members such as a plurality of elastic strands 26.Elastic strands may be formed of an elastomeric material, such as anelastane (for example, LYCRA HYFIT fiber, a product of Invista, Wichita,Kans.). Layers of nonwoven web 25 a, 25 b may be joined together aboutelastic strands 26 by adhesive deposited between the layers, by thermalbonds, by compression bonds, or by a combination thereof. In otherexamples, the one or more elastic members may be strips or a section offilm formed of elastomeric material. Where the elastic member iselongate, it may be desirable that the longer dimension be laterallyoriented, or even substantially aligned with the lateral direction, asstrands 26 are depicted in the figures.

The elastic members can also be formed from various other materials,such as but not limited to, rubbers, styrene ethylbutylene styrene,styrene ethylene propylene styrene, styrene ethylene ethylene propylenestyrene, styrene butadiene styrene, styrene isoprene styrene, polyolefinelastomers, elastomeric polyurethanes, and other elastomeric materialsknown in the art, and combinations thereof. In some examples, theelastic members may be extruded strand elastics with any number ofstrands (or filaments). The elastic members can have a decitex rangingfrom 50 to 2000, or any integer value for any decitex value in thisrange, or any range formed by any of these integer values. The elasticmembers may be in a form of film. Examples of films have been describedin prior patent applications (see, for example, U.S. Pat. App. Pub. No.2010/0040826). The film may be created with a variety of resins combinedin at least one of several sublayers, the latter providing differentbenefits to the film.

Still referring to FIGS. 3-5, during manufacture of the belt structure,the elastic members such as elastic strands 26 may be pre-strainedlengthwise by a desired amount as they are being incorporated into thebelt structure. Upon subsequent relaxation of the belt, the elasticmembers such as elastic strands 26 will contract laterally toward theirunstrained lengths. This causes the layers of nonwoven material 25 a, 25b to gather and form ruffles or rugosities 27 having ridges 28 andvalleys 29 generally transverse to the lengths of the elastic strands26, and extending in the z-direction.

In another example, to adhere the components of the belt laminate, theelastic strands 26 themselves may be individually coated with adhesive(“strand coated”) prior to incorporation into the belt laminate. Variouscoating methods and techniques, including strand coating methods andtechniques, are shown for example in U.S. Pat. Nos. 5,340,648;5,501,756; 5,507,909; 6,077,375; 6,200,635; 6,235,137; 6,361,634;6,561,430; 6,520,237; 6,582,518; 6,610,161; 6,613,146, 6,652,693,6,719,846 and 6,737,102. The adhesive used may be a hot-melt typeadhesive having elasticity and flexibility making it suitable forattaching pre-strained elastic materials to substrates, such as OMNIMELTBLOCKS 22 H2401F, or ZEROCREEP brands such as AVANCE, available fromBostik, Inc., Wauwatosa, Wis.

Referring to FIG. 2A, the rear belt portion 23 may have a greaterlongitudinal dimension (i.e., greater length) than the front beltportion 22. This may help provide greater coverage of the wearer'sbuttocks area in the rear while providing greater comfort in front, viabetter conformity with wearer anatomy and natural body movement. In theexample of FIG. 2A, when the two portions 22, 23 are joined at sideseams with their respective waist edges 34, 35 substantially aligned,however, the rear leg edges 18 will lie below the front leg edges toform a stepped leg edge profile at the seams. If deemed undesirable,this effect may be mitigated by selecting, disposing and/or varyingpre-strain levels among the elastic members as suggested and describedin, for example, U.S. Pat. App. Ser. No. 62/042,387, to laterally drawthe lower rear corners of the rear belt portion inward toward thelongitudinal axis y. A potential desirable result of such practice isschematically suggested in FIG. 6A.

Alternatively, the lower rear corners of the rear belt portion may betrimmed off as suggested in FIGS. 2B and 6B. The lower rear corners maybe trimmed off along straight lines as suggested in FIGS. 2B and 6B, ormay be trimmed off along trim paths (not shown) that are curved andeither concave or convex with respect to the remaining area of the rearbelt portion 23, as may be desired to impart a particular curved rearleg edge profile. In conjunction with such trimming and theconfiguration of elastic strands described above, it may be desired toimpart bonding 40 between layers 25 a, 25 b along edges 18 of rear beltportion 23. Such bonding may serve to prevent any separation of thelayers along edges 18 that may contribute to creating a raggedappearance, and may also help the rear belt portion more effectivelydraw inward laterally toward the central chassis 30, under thecontractive force of the elastic strands below seams 24. Bonding 40 maybe effected by mechanical/compression bonds as described in, forexample, U.S. Pat. Nos. 4,854,984 and 4,919,738, by thermal bonds orwelds, or by deposits of adhesive between layers 25 a, 25 b. Assuggested in FIG. 2B, such bonding may form a pattern along edges 18.Such bonding may be supplemental to any bonding between layers 25 a, 25b generally holding rear belt portion 23 together as a laminatestructure.

Side seams 24 may be permanent or refastenable. Permanent seams may beformed between the front belt portion and the rear belt portion by anybonding mechanism wherein the front and rear belt portions may not beforcibly separated without substantial damage to one or both of thefront and rear belt portions, or without any included mechanism by whichsubstantial reattachment or refastening may be effected. Bonding formingpermanent seams may include compression bonding, thermal bonding/welds,ultrasonic bonding or adhesive bonding. Refastenable seams may be formedbetween the front belt portion and the rear belt portion by anymechanism configured to permit substantially non-destructive forcibleseparation of the front and rear belt portions, and subsequentsubstantial reattachment or refastening at the same locations. Oneexample of such mechanism is a hook-and-loop fastening system, forexample, a VELCRO fastening system. A suitably sized and shaped hookscomponent may be bonded to one of the front or rear belt portions alongthe longitudinal edges thereof, and a suitably sized and shaped loopscomponent may be bonded to the other of the front or rear belt portionsalong the longitudinal edges thereof, in positions in which they may bebrought together and engaged to form seams 24. Examples are depicted inU.S. Pat. App. Ser. Nos. 61/787,416; 61/787,332; 61/666,065.

Absorbent Structure

The absorbent structure 115 is a three-dimensional structure including asubstrate layer 116 and an absorbent layer 117 including absorbentpolymer particles, and optionally cellulose, supported by, andimmobilized on, said substrate layer 116. Examples of absorbentstructures 115 are illustrated in FIGS. 8, 10A, 10B, 14, 15A and 15B.

The substrate layer 116 of the absorbent structure may be any materialcapable of supporting the absorbent polymer particles. It may be a webor sheet material, such as foam, film, woven and/or nonwoven material.

Nonwoven materials and processes for making them are generally known inthe art. Generally, processes for making nonwoven materials include twosteps: depositing and accumulating fibers to the desired basis weightonto a forming surface, and consolidating and bonding the accumulatedfibers to form a coherent web. The first step may include spunlaying,meltblowing, carding, airlaying, wetlaying, coforming and combinationsthereof. The bonding step may include hydroentanglement, coldcalendering, hot calendering, through air thermal bonding, chemicalbonding, needle punching, and combinations thereof.

The nonwoven material may be a laminate. The laminate may includespunbond layer(s) (S), and/or meltblown layer(s) (M), and/or cardedlayer(s) (C). Suitable laminates include, but are not limited to, SS,SSS, SMS or SMMS. The nonwoven material may have a basis weight fromabout 5 to 100 gsm, or from about 8 to 40 gsm, or from about 8 to 30gsm. Woven or nonwoven materials may include natural fibers or syntheticfibers or combinations thereof. The substrate layer 116 and theabsorbent layer 117 may be coextensive or the substrate layer 116 may beslightly longer and wider than the absorbent layer 117 (as suggested inFIGS. 8, 10A, 10B, 14 and 15.

The absorbent layer 117 may include absorbent polymer particles 150, andoptionally cellulose. The absorbent layer may include absorbent polymerin other forms such as absorbent polymer fibers. Absorbent polymerparticles will be described in further detail below. The absorbentpolymer particles may be used alone or in combination with othermaterials. In some examples, the absorbent layer includes absorbentpolymer particles combined with cellulose. “Cellulose” as used hereinrefers to comminuted wood pulp in the form of fibers, sometimes alsoreferred in the art as “air-felt”. In some examples, the absorbent layerincludes more than 70%, or more than 80%, or more than 90%, or more than95% or even 100% by weight of absorbent polymer particles. In some otherexamples, the absorbent layer includes absorbent polymer particles andless than 5% by weight of cellulose, or less than 2% by weight ofcellulose, or even substantially no cellulose. In examples wherein theabsorbent layer is cellulose free, the only absorbent material in theabsorbent layer is the absorbent polymer (particles, fibers, etc.). Theresulting absorbent structures have a reduced thickness in the dry statecompared to conventional absorbent structure including cellulosicfibers. The reduced thickness helps to improve the fit and comfort ofthe absorbent article for the wearer.

The absorbent layer 117 may include at least two main channels 126.Referring to FIGS. 2A, 2B and 8-14, “channels” as used herein refers totroughs or other identifiable elongate passageways through the depositof absorbent polymer particles of the absorbent layer, partially orentirely extending through the z-direction thickness of the absorbentlayer 117 and characterized by areas of comparatively reduced mass perunit spatial volume density of absorbent polymer particles in the spaceoccupied by the absorbent structure, or even by areas that aresubstantially free of absorbent polymer particles, i.e. substantially noabsorbent polymer particles are present in such volume (longitudinalchannel or secondary channel) of an absorbent structure. The channelsmay have two shorter boundaries 128 (in the shortest dimension) at theirends and two longer boundaries 127 (in the longest dimension) alongtheir sides, connecting the shorter boundaries. The shorter boundariesmay be straight (e.g., perpendicular to the longer boundaries), orangled, or curved. The channels may have an average width w of at least3 mm (the average width of a channel is defined as the average distancebetween the longer boundaries), or of at least 4% of the transversewidth N of the absorbent layer.

The channels may be permanent. By permanent, it is meant that theintegrity of the channels is substantially maintained both in dry stateand wet state, i.e. the channels are substantially resistant to theeffects of wetting (e.g., structure is maintained by materials that areinsoluble in water), and substantially withstand mechanical stresses inthe materials caused by swelling of absorbent polymer particles,pressure within the structure resulting therefrom, and the wearer's bodymovements. Permanent channels may be formed by immobilizing theabsorbent polymer particles on the substrate layer, such as by applyinga thermoplastic adhesive material over the absorbent layer. Theabsorbent layer of the present disclosure may also include permanentchannels formed by permanently bonding of a first substrate layer (116)and a second substrate layer (116′) together along the channels,thereby, in one example, forming chambers that separate and containabsorbent polymer particle deposits and thereby define the channelstherethrough. Adhesive may be used to bond the substrate layers 116,116′ together along the channels, but it is possible to bond thesubstrate layers together via other means, for example, ultrasonicbonding, pressure bonding or thermal bonding. The supporting layers maybe continuously bonded or intermittently bonded along the channels.

The absorbent layer may have two channels 126 located in the absorbentlayer 117 such that the absorbent layer is divided by channels intothree sections in the crotch region 123. As shown in FIGS. 2A, 2B and8-10, the channels may be present in the crotch region of the absorbentlayer. In some examples, the two channels may extend longitudinallyalong at least 15%, or at least 20% or at least 30% and up to 50%, or upto 70% or up 90% of the length M of the absorbent layer (i.e. they mayextend over a distance L which is at least 15% and up to 50%, or up to70% or up 90% of the length M of the absorbent layer). In some examples,the channels may be present only in the crotch region 123. When presentonly in the crotch region, the channels may extend over the wholelongitudinal dimension of the crotch region, e.g. 50% of the length M ofthe absorbent layer, or they may extend in only part of the crotchregion, i.e. from at least 15%, or at least 20% or at least 30% to 40%,or to 45% or to less than 50% of the length of the absorbent layer. Insome examples, the channels 126 may be present in the crotch region, orpart thereof, and part of the front region and/or part of the backregion (such as shown in FIGS. 8-10). In some examples, the channels maybe present in the front and crotch regions, i.e. the channels extendfrom the crotch region (or part thereof) into the front region. In someexamples, the channels may be present in the back and crotch regions,i.e. the channels extend from the crotch region (or part thereof) intothe back region. The channels 126 may be mirror images of one anotherwith respect to the longitudinal axis y of the absorbent layer 117, i.e.the channel in one longitudinal region 120 may be mirror image of thelongitudinal main channel in the other longitudinal region of theabsorbent layer 117.

In some examples, it may be desired that the channels 126 do not extendall of the way to one or both of the transverse edges 119 (front andback) of the absorbent layer 117, i.e. from one transverse edge to theother. The absorbent layer may include, along each transverse edge andadjacent to said edge, an end deposit of absorbent polymer particlesfree of channels which extends in the transverse dimension of theabsorbent layer from one longitudinal edge 118 of the absorbent layer117, to the other. Such end deposits may have respectively a width F′ orG′ which are at least 5% of the longitudinal dimension of the absorbentlayer (i.e. a width which is at least 5% of the length of the absorbentlayer). In other words, the smallest distance F′ or G′ between the edgeof a channel and the transverse edge of the absorbent layer is at least5% of the longitudinal dimension M of the absorbent layer. In someexamples, the width F′ or G′ is at least from 5% to 15%, or to 10% ofthe longitudinal dimension of the absorbent layer.

Furthermore, in order to reduce the risk of fluid leakage and run-off,it may be desired that the channels do not extend to the longitudinaledges 118 of the absorbent layer 117. The absorbent layer may include,along each longitudinal edge, a side deposit of absorbent polymerparticles free of channels, which extends the length M of the absorbentlayer from one transverse edge 119 to the other. Such side deposits mayhave respectively a width I′ or H′ which is at least 5%, or at least10%, or at least 12% to 25% of the width N of the absorbent layer in agiven region (i.e. a width I′ or H′ which is at least 5% of the width Nof the absorbent layer). In other words, the minimum distance I′ or H′between the edge of a channel and the longitudinal edge 118 of theabsorbent layer is at least from 5% to 25% of the transverse dimensionof the absorbent layer. For example, the distance I′ or H′ in the crotchregion may correspond to at least 5%, or to at least 10% or at least 12%of the transverse dimension N of the absorbent layer in said crotchregion. In some examples, the distance I′ and/or H′ is of 10 mm, or 15mm or 20 mm.

The channels may be substantially straight, and may run substantiallyparallel to the longitudinal axis y of the absorbent layer (as shownschematically in FIGS. 10A, 10B and 11A). Straight channels may serve ashinge structures in the absorbent structure, which may help enable theabsorbent structure to flex longitudinally and thereby better conform tothe wearer's anatomy along the transverse direction through the crotchregion, and may also help enable the absorbent structure to form acontaining shape better suited to receiving and containing liquidexudate before it is completely absorbed, when the pant is worn.Longitudinally extended channels also may help improve fluidtransportation and distribution along the length of the deposits ofabsorbent polymer particles within the absorbent structure, and therebymay help speed liquid absorption.

Alternatively, the channels may be curved and/or arcuate, as suggestedin FIGS. 8, 9, 12 and 13. Longitudinally extended but curved channelsmay also serve as hinge structures in the absorbent structure which mayhelp enable the absorbent structure to flex longitudinally and therebyconform to the wearer's anatomy along the transverse direction in thecrotch region. Thus, the channels may contribute to imparting acomfortable and superior fit in addition to permitting improved liquidtransportation and distribution.

The channels 126 may include oblique channels, as suggested in FIGS.11C, 12 and 13, i.e., substantially straight channels oriented at anangle θ of up to 30 degrees, or up to 20 degrees, or up to 10 degreeswith respect to the longitudinal central axis y of the absorbentstructure.

In some other alternatives, the channels may be angled channels, assuggested in FIG. 11D. Angled channels are channels made of two or moreportions connected under an angle σ to one another. Angled channels maybe made of two portions connected under an angle β of at least 150degrees, or at least 160 degrees or at least 170 degrees.

The channels 126 may have an average width w of from 3 mm to 15 mm, orfrom 4 mm to 14 mm or from 5 mm to 12 mm (the average width of a channelis the average distance between its longer boundaries 127). The averagewidth of the channels may be at least 4% of the width of the absorbentlayer, or at least 7% and up to 15%, or 20% or 25%. In some examples,the channels may have an average width w of from 3 mm to 18 mm, or from5 mm to 15 mm or from 6 to 10 mm.

The channels 126 may be separated in the crotch region by a distance D(illustrated in FIG. 8) of at least 5%, or at least 10%, or at least20%, or at least 25% of the transverse dimension (width) of theabsorbent layer in said crotch region. It is believed that when thesetwo channels are separated by a distance of at least 5% of thetransverse dimension of the absorbent layer in the crotch region, theabsorbent structure is more likely to conform to the wearer's anatomyalong the transverse direction and form a containing structure in thecrotch region when the pant is worn. In some examples, the channels maybe separated in the crotch region by a distance of at least 10 mm, or atleast 15 mm, or at least 20 mm, or at least 30 mm. In some examples, thedistance separating the channels in the crotch region is from 20 to 30mm.

Longitudinally-oriented channels formed in the absorbent layer may helptransport and distribute liquid (e.g., urine) along the lengths of thedeposits of absorbent polymer particles in the absorbent layer, andthereby help speed acquisition and absorption. However, thecorrespondingly-defined longitudinal chambers or other structurescontaining or defining the deposits of absorbent polymer particles maydevelop elevated internal pressure as the particles absorb liquid,swell, and press against each other. This pressure may have alongitudinal, structural stiffening effect on the absorbent structure.The internal pressure causes the absorbent layer to tend to straightenlongitudinally, rather than easily curve around and beneath the wearer'slower torso as the absorbent structure wraps between the wearer's legs.This stiffening effect may help prevent creation of a droopy or saggyappearance of the article when wetted. On the other hand, it has beendiscovered, as schematically illustrated in FIG. 7, this stiffeningeffect can cause the frontward and rearward ends of the absorbentstructure to bulge away from the wearer's body in frontward and rearwarddirections, creating noticeable, unsightly, and potentiallyuncomfortable bulges 219 proximate the frontward and rearward ends ofthe absorbent layer. It has been discovered that this effect may bemitigated by one or more of several alternative configurations in a pantstructure.

As suggested in FIGS. 12 and 13, the absorbent layer may includeadditional secondary channels 126′ to further increase the fluidtransportation and/or fit of the absorbent article. The abovedescription of channels may equally apply to any of said secondarychannels 126′. However, in some examples, the secondary channels may beshorter than the channels described above.

The longitudinal secondary channels may extend over a distance V′ of atleast 10%, or at least 15%, or at least 20% of the longitudinaldimension M of the absorbent layer (as illustrated in FIG. 13). They mayextend up to 90% of the longitudinal dimension of the absorbent layer.The longitudinal secondary channels may extend up to 30% or 45% of thelongitudinal dimension of the absorbent layer.

The absorbent layer may include one or more secondary channels, such astwo, three, four, five or six. Secondary channels may be present in thefront region, back region and/or crotch region of the absorbent layer.The absorbent layer may include an even number of secondary channels.The secondary channels may be distributed in the absorbent layer suchthat each longitudinal region of the absorbent layer includes an equalnumber of secondary channels. In some examples, the longitudinal regionsincluding the channels (i.e. main longitudinal channels and secondarychannels) are mirror images of each other with respect to the centrallongitudinal axis of the absorbent layer.

As suggested in FIGS. 14 and 17-19, in other examples the absorbentlayer also may include one or more transverse secondary channels 129.Transverse channels 129 may have their longer dimensions orientedpredominately in the transverse direction, or even be substantiallyperpendicular to the longitudinal axis y of absorbent layer 117.Transverse channels may serve as transverse hinge structures that canenable the absorbent structure to flex laterally and thereby conform tothe wearer's anatomy along the longitudinal direction as it wraps aroundand beneath the wearer's lower torso between the legs from front toback. This may help mitigate the longitudinal stiffening effects ofchannels as illustrated in FIG. 7.

Transverse channels may be disposed above the lower edge 21 of the belt(FIG. 17), or below it (FIG. 18), although for better appearance andcontrol of the shape of the loaded absorbent layer, when only one or twotransverse channels are present, it may be preferred that one or both bedisposed above the lower edge of the belt (as suggested in FIG. 17). Inalternative examples, one or more transverse channels may be disposedbetween the lateral axis x and the lower edge 21 of the front beltportion and/or the rear belt portion.

Transversely-oriented secondary channels 129 may extend over a distanceof at least 10%, or at least 15%, or at least 20%, of width N of theabsorbent layer. They may extend up to 90% of the transverse dimensionof the absorbent layer. The transverse secondary channels 129 may extendup to 30% or 45% of the transverse dimension of the absorbent layer. Insome examples, transverse channels 129 may connect main channels 126, assuggested in FIG. 19. In some examples, transverse channels 129 may bedistinct and separate from main channels 126, as suggested in FIGS. 14,17 and 18.

The channels may be sized and located in the absorbent layer such that acentral deposit of absorbent polymer particles extending along thecentral longitudinal axis of the absorbent layer (and including saidaxis) from one transverse edge to the other one, and having a width D′of at least 5%, or at least 10% and up to 60%, or up to 70%, or up to75% of the transverse dimension of the absorbent layer remains free ofchannels. The absorbent polymer particles may be substantiallycontinuously present in such a central deposit. For example, a centraldeposit may have a width D′ of at least 5 mm, or at least 10 mm, or atleast 15 mm or 20 mm and up to 70 mm or up to 40 mm. The absence ofchannels in such a central deposit is advantageous since it at leastinhibits the diaper from taking an inverted V-shape configuration (alongthe transverse direction) in the crotch region when the pant is worn. Aninverted V-shape configuration may increase the risk of liquid leakagealong the leg openings. In some examples, the average basis weight ofabsorbent polymer particles in such a central deposit is relativelyhigh, i.e. at least 350 gsm and up to 1000 gsm, or for example from 450gsm to 750 gsm, and higher than the basis weight at other locations ofthe absorbent layer.

In other examples, the absorbent layer structure defining the channels126 and corresponding longitudinally-oriented volumes containingdeposits of absorbent polymer particles may be imparted with featuresthat cause the structure to change from a first configuration when dryto a second configuration when wetted to, e.g., one-quarter, one-third,one-half, two-thirds or more of the total absorbent capacity (by weightof absorbed liquid) of the absorbent layer. For example, materials usedto form longitudinal chambers or other structures containing or definingcorrespondingly longitudinally-oriented deposits of absorbent polymerparticles, and defining channels among/between them, may be configuredto change structure when wetted. In one example, illustrated withreference to FIGS. 15A and 15B, an absorbent structure 115 may have afirst configuration when dry (e.g., FIG. 15A) and a second configurationwhen wetted (e.g., FIG. 15B), e.g., to more than half of its absorbentcapacity. One mechanism that may be used to enable this may be a watersoluble or otherwise releasable adhesive affixing substrate layers 116and 116′ together along, and thereby defining, channels 126. Uponwetting and/or outward pressure against layers 116 and 116′ from theswelling deposits of absorbent polymer particles, the adhesive releases,and the swelling deposits of absorbent polymer particles are permittedto expand into the volume previously defined by the channels 126, whichthen may reduce in size or even disappear as suggested in FIG. 15B. Thismay have the effect of relieving pressure within the absorbent layer 117and absorbent structure 115, which may lessen the longitudinalstiffening effects described above. Thus, advantages of channels(flexibility, conformability and liquid distribution enhancement) may beenjoyed at times before the pant is substantially wetted, while adisadvantage of channels (longitudinal stiffness) may be mitigated attimes after the pant has been substantially wetted.

This changing channel structure may be utilized alone or may be combinedwith permanent channel structures of any desired configuration,including but not limited to any configuration described herein.

In a further example, main channels 126 may have a length in thelongitudinal direction. The length may be divided into three, four, fiveor more sublengths. The structure defining the channels may beconfigured to permanently define the channels along one or more of thesublengths, but to changeably define the channels along other of thesublengths, such that they reduce in size or disappear upon wetting. Inone example, channels are permanently defined in areas proximate thelateral axis x of the pant, and are changeably/releaseably defined,e.g., as described above, in areas further away from the lateral axis x.In some examples, one or more sublengths at and/or proximate the ends ofthe channels are changeable/releaseable upon wetting. In one particularexample, one or more longitudinal main channels 126 are divided intofive sublengths. The intermediate sublength may be permanently defined,while the two sublengths toward each end of the channel may bechangeably/releaseably defined such that they reduce in size ordisappear upon wetting as described above. In alternative examplesincluding one or more longitudinally oriented channels, a portion of thechannel(s) may be permanent and a portion of the channel(s) may betemporary or releasable. The temporary portions of the channel(s) may bedisposed between the lateral axis x and a lower edge 21 of the belt. Insome examples the temporary portion of the channel may be disposed atone or both of the ends of the channel and may occupy between 10 and 25%of the dry length of the channel at one or both ends. The temporaryportions of the channel may also be disposed intermittently along thelength of the channel and may alternate with permanent portions of thechannel.

In another alternative, which may if desired be combined with anycombination of the channel features described above, the absorbent layer117 may extend longitudinally such that one or both ends 119 thereof aredisposed beneath one or all layers of belt portions 22, 23 when the pantis worn. Non-limiting examples are suggested in FIGS. 16A-19. In aparticular aspect, all longitudinally-oriented main channels 126 mayextend such that one (FIGS. 16A, 16B) or both (FIG. 16C) ends thereofare disposed to the wearer side of one or both belt portions 22, 23 whenthe pant is worn. Non-limiting examples are suggested in FIGS. 16A-16Dand 19. As a result, the ends of longitudinal chambers or otherstructures containing or defining deposits of absorbent polymerparticles will, accordingly, be disposed to the wearer side of one orboth belt portions when the pant is worn. In such a configuration, whenthe longitudinal chambers or other structures containing or definingdeposits of absorbent polymer particles become longitudinally stiff frominternal pressure as a result of liquid absorption, one or both endsthereof will be subject to lateral tensile forces in the beltportion(s). This may help restrain the end(s) of absorbent layer andhold them closer to the wearer's body, and thereby help prevent themfrom forming the bulges 219 such as are schematically illustrated inFIG. 7.

The absorbent layer, absorbent structure and/or configuration ofchannels may also have any features described in U.S. Pat. App. Pub.Nos. US2014/0163511; US2014/0163503; US2014/0163501; US2014/0163500;US2012/0316526; US2012/0316528; US2014/0163501; and US2014/0371701.

Absorbent Layer

The absorbent layer may include absorbent polymer particles 150 alone orin combination with other materials, such as cellulose fiber. Theabsorbent polymer particles may be immobilized on a substrate layer by,for example, a thermoplastic adhesive material 140.

Absorbent polymer particles suitable for use in the absorbent layer mayinclude any absorbent polymer particles known from superabsorbentliterature, for example such as described in Modern SuperabsorbentPolymer Technology, F. L. Buchholz, A. T. Graham, Wiley 1998.

The absorbent polymer particles may be spherical, spherical-like,ellipsoid, or irregularly shaped, such as ovoid-shaped particles of thekind that may be obtained from inverse phase suspension polymerizations.The particles may, optionally, be agglomerated at least to some extentto form larger irregular agglomerations of particles.

The absorbent polymer particles may be selected from among polyacrylatesand polyacrylate based materials that are internally and/or surfacecross-linked, such as for example partially neutralized cross-linkedpolyacrylates or acid polyacrylate. Examples of absorbent polymerparticles suitable in the present disclosure are described for instancein the PCT Pat. App. Nos. WO 07/047598, WO 07/046052, WO2009/155265 andWO2009/155264.

In alternative examples, the absorbent layer may be substantiallycellulose-free. Airfelt and other cellulose fiber have been used asabsorbent fillers in absorbent cores of disposable diapers. Such fiberpossesses absorbent properties and imparts some absorption capacity toan absorbent layer, but also may be included to provide a structuralmatrix to hold dispersed particles of absorbent polymer particles. Whileinclusion of such particles enhances absorption capacity, keeping suchparticles suitably dispersed may be important to prevent the particlesfrom “gel-blocking” in use as they swell with absorbed liquid and blockthe passageways therebetween which allow liquid to move through depositsthereof, compromising absorption capacity. The inclusion of airfelt orother cellulose fiber as a matrix for absorbent polymer particles canserve to reduce or prevent gel-blocking. However, it also imparts bulkto an absorbent layer, even before absorption of any liquids. To reducethe overall size and/or thickness of the absorbent layer, and therebyimprove wearer comfort and reduce the bulkiness of the pant for purposesof packaging and shipping volume efficiency, it may be desired toconstruct an absorbent core using the lowest volumes of core materialspossible within performance constraints. Toward this end, examples ofsuitable materials and constructions for a suitable absorbent structureare described in, but are not limited to, U.S. patent application Ser.Nos. 12/141,122; 12/141,124; 12/141,126; 12/141,128; 12/141,130;12/141,132; 12/141,134; 12/141,141; 12/141,143; and Ser. No. 12/141,146;and WO2008/155699. Generally, these applications describe absorbentlayer constructions that minimize or eliminate the need for andinclusion of airfelt or other forms of cellulose fiber in combinationwith particles of absorbent polymer particles (“substantiallycellulose-free” structures). Suitable methods for forming deposits ofabsorbent polymer particles are additionally disclosed in, for example,EP 1621167 A2, EP 1913914 A2 and EP 2238953 A2.

The absorbent polymer particles may be immobilized on the substratelayer. Immobilization may be achieved by applying a thermoplasticadhesive material, which holds and immobilizes the absorbent polymerparticles, and cellulose when present, on the substrate layer. Somethermoplastic adhesive material may also penetrate into the layer ofabsorbent polymer particles and into the substrate layer to providefurther immobilization and affixation. The thermoplastic adhesivematerial may not only help in immobilizing the absorbent polymerparticles on the substrate layer but also may help in maintaining theintegrity of the channels. The thermoplastic adhesive material avoidsthat a significant amount of absorbent polymer particles migrates intothe channels.

Thermoplastic adhesive materials suitable for use in the presentdisclosure includes hot melt adhesives including at least athermoplastic polymer in combination with a plasticizer and otherthermoplastic diluents such as tackifying resins and additives such asantioxidants. Example suitable hot melt adhesive materials are describedin EP 1447067 A2.

In some examples, the absorbent core may include an acquisition system,which is disposed between the topsheet and the wearer facing side of theabsorbent structure. The acquisition system may serve as a temporaryreservoir for liquid until the absorbent structure can absorb theliquid. The acquisition system may include a single layer or multiplelayers, such as an upper acquisition layer facing towards the wearer'sskin and a lower acquisition layer facing the garment of the wearer. Theacquisition system may be in direct contact with the absorbentstructure. In these examples, the acquisition system may fill in thechannels or portions thereof of the absorbent structure. In someexamples, the acquisition system, or one layer thereof, may be bonded tothe substrate layer which undulates into the channels thus providing anundulating profile to said acquisition system.

As suggested in FIG. 15, the absorbent layer of the absorbent structuremay include an acquisition/distribution layer 131. Layer 131 may havethe form of, e.g., a layer, mat or other body formed of or including,e.g., comminuted cellulose fibers, or other hydrophilic natural,semi-synthetic or synthetic fibers or other material that may be used toform a mat, layer or other body.

In one example, one or both of the upper and lower acquisition layersmay include a non-woven, which may be hydrophilic. Further, according toa certain example, one or both of the upper and lower acquisition layersmay include the chemically cross-linked cellulosic fibers, which may ormay not form part of a nonwoven material. According to an example, theupper acquisition layer may include a nonwoven, without the cross-linkedcellulosic fibers, and the lower acquisition layer may include thechemically cross-linked cellulosic fibers. Further, according to anexample, the lower acquisition layer may include the chemicallycross-linked cellulosic fibers mixed with other fibers such as naturalor synthetic polymeric fibers. According to example examples, such othernatural or synthetic polymeric fibers may include high surface areafibers, thermoplastic binding fibers, polyethylene fibers, polypropylenefibers, PET fibers, rayon fibers, lyocell fibers, eucalyptus fibers andmixtures thereof. Suitable non-woven materials for the upper and loweracquisition layers include, but are not limited to SMS material,including a spunbonded, a melt-blown and a further spunbonded layer. Incertain examples, permanently hydrophilic nonwovens, and in particular,nonwovens with durably hydrophilic coatings are desirable. Anothersuitable example includes an SMMS-structure. In certain examples, thenonwovens are porous.

Other Belt/Chassis Features

Referring to FIG. 20, elastic members such as elastic strands 26 may beconfigured within the front and/or rear belt portion(s) 22, 23 such thatthey are present in lower side zones 22″, 23″ of the belt portions, butnot present in part of all of lower laterally central zones 22′, 23′that overlie the chassis 30. Thus, one or both belt portions may beconfigured such that one or more of the layers that sandwich the elasticstrands 26 are present in lower central zones 22′, 23′ of the beltportions, such as nonwoven layers 25 a, 25 b (see FIG. 3), withoutelastic stretch enabled by the presence pre-strained elastic members andruffles of laterally gathered material. In the central zones 22′, 23′that overlie the chassis, the nonwoven layer(s) of one or both beltportions 22, 23 may be disposed and affixed to the chassis material(s)(such as the backsheet) such that they overlie the chassis in laterallyextended condition, i.e., they do not have longitudinal ruffles orrugosities (e.g., ruffles or rugosities 27, illustrated in FIGS. 4 and5) that would otherwise be imparted by lateral contraction ofpre-strained, sandwiched lateral elastic strands. In this configuration,the fully extended belt layer material(s) overlying the chassis 30 inlower central zones 22′, 23′, being without longitudinal ruffles andthereby being unable or less able to elastically stretch laterally ascompared to the other elasticized, ruffled zones of the belt portions,are configured to provide greater resistance to lateral expansion,supplementing that of the chassis materials and helping to support andrestrain the ends of absorbent layer 117. As a result, protrusion ofoutward bulges 219 upon absorption of liquid by the absorbent layer 117(such as those illustrated in FIG. 7), may be reduced. This feature maybe combined with any of the channel configurations described above, forpotentially synergistic effects in reducing protrusion of bulges of theabsorbent layer 117 as described above. Thus, in one example illustratedin FIG. 20, the forward ends of main longitudinal channels 126 may bedisposed beneath (to the wearer-facing side) of non-elasticized lowercentral zone 22′ of front belt portion 22. In some examples, the beltportions and the chassis may be configured to have features described inPCT/CN2014/094890, which describes additional examples of beltconfigurations having non-elasticized portions overlying the chassis.

In a further example, one or more elastic strands 26 present in thelower side zones 22″, 23″ may be selected (e.g., by decitex and/ortensile modulus) and/or configured (e.g., by longitudinal numericalcount/unit longitudinal dimension of the belt, and/or amount of impartedpre-strain) to impart greater tensile contractive force to the beltstructure in one or more of the lower side zones 22″, 23″ than in theupper zone(s) closer to the waist edges. This latter example may helpenhance comfort of the pant, when worn, by providing for relativelylesser lateral contractive tensile force about the waist band areas andwaist edges, and relatively greater lateral contractive tensile forcewith greater support, resistance to bulging of the channeled absorbentlayer, and anchoring of the pant about the wearer's lower hips. Thus,one or more of the elastic strands 26 in one or both of lower side zones22″, 23″ may have one or more of greater decitex, greater tensilemodulus, greater number of strands 26 per unit longitudinal length ofthe belt portion, or greater amount of pre-strain, than one or more ofthe elastic strands 26 in the upper zone(s) closer to the waist edges inthe same front or rear belt portion. This feature may be incorporatedalone, or in combination with, the inclusion of non-elasticized centralzone(s) 22′, 23′ of the belt described immediately above.

The dimensions and values disclosed herein are not to be understood asbeing strictly limited to the exact numerical values recited. Instead,unless otherwise specified, each such dimension is intended to mean boththe recited value and a functionally equivalent range surrounding thatvalue. For example, a dimension disclosed as “40 mm” is intended to mean“about 40 mm.”

Every document cited herein, including any cross referenced or relatedpatent or application and any patent application or patent to which thisapplication claims priority or benefit thereof, is hereby incorporatedherein by reference in its entirety unless expressly excluded orotherwise limited. The citation of any document is not an admission thatit is prior art with respect to any invention disclosed or claimedherein or that it alone, or in any combination with any other referenceor references, teaches, suggests or discloses any such invention.Further, to the extent that any meaning or definition of a term in thisdocument conflicts with any meaning or definition of the same term in adocument incorporated by reference, the meaning or definition assignedto that term in this document shall govern.

While particular examples of the present invention have been illustratedand described, it would be obvious to those skilled in the art thatvarious other changes and modifications may be made without departingfrom the spirit and scope of the invention. It is therefore intended tocover in the appended claims all such changes and modifications that arewithin the scope of this invention.

What is claimed is:
 1. An absorbent article comprising: a centrallateral axis, a central longitudinal axis extending in a directionperpendicular to the central lateral axis; a front region, rear regionand crotch region between the front and rear regions; a topsheet, abacksheet and an absorbent structure positioned at least partiallybetween the topsheet and backsheet; the absorbent structure having anabsorbent layer comprising a length M, a width N, and opposingtransverse edges and longitudinal edges; wherein the absorbent layercomprises an absorbent material; and wherein the absorbent materialdefines: at least two longitudinal main channels each extending over adistance L that is at least 15% of the length of the absorbent layer M,and a transverse channel, wherein the transverse channel connects two ofthe at least two longitudinal main channels, wherein the transversechannel and/or at least one of the longitudinal main channels comprisesa temporary portion.
 2. The absorbent article of claim 1 wherein thelongitudinal main channels each comprise one or more permanent portions.3. The absorbent article of claim 2 wherein at least one longitudinalmain channel comprises a permanent portion that overlaps the centrallateral axis.
 4. The absorbent article of claim 1 wherein one of the atleast two longitudinal main channels is disposed a first side of thecentral longitudinal axis and another of the at least two longitudinalmain channels is disposed on a second side of the central longitudinalaxis.
 5. The absorbent article of claim 1 wherein at least twolongitudinal main channels do not extend to the longitudinal edges ortransverse edges of the absorbent layer.
 6. The absorbent article ofclaim 1 wherein the transverse channel does not extend to thelongitudinal edges or transverse edges of the absorbent layer.
 7. Theabsorbent article of claim 1 wherein the at least two longitudinal mainchannels are curved.
 8. The absorbent article of claim 1 wherein thetransverse channel is curved.
 9. The absorbent article of claim 1wherein the transverse channel is present in the rear region.
 10. Theabsorbent article of claim 1 wherein two of the at least twolongitudinal main channels are separated in the crotch region by adistance D that is at 10% of the width of the absorbent layer N.
 11. Theabsorbent article of claim 1 wherein two of the at least twolongitudinal main channels are separated in the crotch region by adistance D of at least 15 mm.
 12. The absorbent article of claim 1wherein the transverse channel extends a transverse distance of at least15% or the width of the absorbent layer N.
 13. The absorbent article ofclaim 1 wherein the absorbent material comprises absorbent polymerparticles and cellulose fibers.
 14. The absorbent article of claim 1wherein the temporary portion reduces in size upon wetting.
 15. Theabsorbent article of claim 1 wherein the absorbent material layer isdisposed between a first substrate and a second substrate and wherein inthe temporary portion, the first and second substrates are bondedtogether in an article dry state and wherein the first substratereleases from the second substrate in an article wet state.
 16. Theabsorbent article of claim 1 further comprising anacquisition/distribution layer and wherein at least one of the topsheetand the acquisition/distribution layer is generally planar in naturesuch that the topsheet and the acquisition/distribution layer bridgesover the channels.
 17. An absorbent article comprising: a) a top sheet;b) a backsheet; c) an absorbent structure disposed between the topsheetand the backsheet, the absorbent structure comprising a first substrate,a second substrate, and an absorbent material layer disposed between thefirst substrate and the second substrate and comprising a combination ofabsorbent polymer particles and wood pulp fibers; d) a channel definedin the absorbent material layer that is substantially free of thecombination of absorbent polymer particles and wood pulp fibers; e)wherein the channel comprises at least two permanent portions; f)wherein the channel comprises a temporary portion; and g) wherein thetemporary portion resides between two of the at least two permanentportions.
 18. The absorbent article of claim 17 wherein the channel iscurved.
 19. The absorbent article of claim 17 further comprising anacquisition/distribution layer between the topsheet and the absorbentstructure.
 20. The absorbent article of claim 19 wherein at least one ofthe topsheet and the acquisition/distribution layer is generally planarin nature such that the topsheet and the acquisition/distribution layerbridges over the channel.
 21. The absorbent article of claim 17 whereinthe at least two permanent portions overlap the central lateral axis.22. The absorbent article of claim 17 wherein the temporary portionreduces in size upon wetting.
 23. The absorbent article of claim 1wherein in the permanent portion, the first substrate is bonded to thesecond substrate in both an article dry state and wet state, and in thetemporary portion, the first and second substrates are bonded togetherin the article dry state but the first substrate releases from thesecond substrate in the article wet state.